Red Sox, Athletics Pull Off Blockbuster Trade On Deadline Day

According to multiple reports, the AL West leaders also got outfielder Jonny Gomes and cash from the Red Sox in exchange for outfielder Yoenis Cespedes.

Boston will also receive the second pick in the competitive balance Comp B round in next year's draft.

After already acquiring Jeff Samardzija and Jason Hammel from the Chicago Cubs this summer, the A's continued to strengthen their pitching staff with the addition of Lester.

Lester, 30, was pulled from his scheduled start on Wednesday amid the swirling trade talks. He had a 10-7 record with a 2.52 ERA in 21 outings this season for Boston.

With aspirations of winning a World Series title, Oakland added a player in Lester who has flourished pitching in October. He has a career postseason ERA of 2.11 and won two rings during his time in Boston.

For the 33-year-old Gomes, he will begin a second stint with the A's as he was on the 2012 squad. He is batting .234 with six home runs and 32 RBI over 78 games this season.

The Red Sox landed a power bat in the 28-year-old Cespedes. The two-time defending Home Run Derby champ has hit .256 with 17 homers and 67 RBI in 101 games this year.